Radio receiving system



Fi m/n i, 1932. c. R. ROWE RADIO RECEIVING SYSTEM Filed July 24. 19:51

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INVENTOR B H.EDWE fi U ATTORNEY ww xw Patented Nov. 1, 1932 umrsn stares issazao PATENT mm "GHARLES R. ROWE, OF MAPLEWOOD, NEW JERSEY, ASSIGNOR T WIRED RADIO, INC

OF NEW YORK, N. Y., A CORPORATION OF DELAWARE RADIO RECEIVING svsrn rc Application filed July 24, 1931. Serial nutsasvs;

.15;consumers who are equipped with the proper receiving apparatus.

My invention is dlrected to providing a common receiving system for the selective reception of space radio or wired radio sig-' zo'nals whereby a wide range of program entertainment can be made available to a user without undue complication or multiplication of apparatus. There are several problems, I however, to be encountered in producing a duplex radio system for the reception of either wired radio or space radio signals. One of these is that the frequency ranges employed in spaceradio broadcasting are much higher than those employed in carrier fre Boquency or wired radio broadcasting. The' carrier frequencies, commonly employed in space broadcasting are of the order of 500- 1500 kilocycles, whereas carrier frequencies used for wired radio purposes are anywhere -in the super-audibility range up to 100 kilocycles. It will be evident that apparatus especially designed for handling space radio frequencies willnot be as efficiently responsive to wired radio frequencies. This is par lfl ticularly true of transformers for coupling thermionic tube circuits in a receiving system.

In space radio broadcasting the signal level of the received signal energy is extremely small, being of the order of a few micro-volts.

On the other hand, in wired radio broadcasting systems, the signal level is much higher,

it being notunusual to findsignalingenergy at the receiver of the order of one-half volt or more. Certain types of space radio receiving 5 organizations have several stages of radio freamplification stages for wired radio purquency amplification and but one stage of audio frequency amplification. It will be obvious, from a comparison of the magnitudes of the signaling energy available by space radio and wired radio, that it is not necessary and undesirable to employ all of the amplification stages used in space radio reception-for the purpose of amplifying the wired radio signals. This means, then, that only selected ones of the space radio amplification stages are to be employed for wired radio purposes.

One of the objects of my invention consists in providing a radio receiving organization' for the selective reception of either Wired radio or space radio signals.

Another object consists in providing a radio receiving system having a plurality ofv amplification stages for space radio reception and means for utilizing selected ones of said poses.

Another object comprises producing a radio receiving system having a. plurality of space discharge tubes together with means for selectively connecting certain of said space discharge tubes by circuit paths of different frequency characteristics.

I accomplish the above desirable objects in a novel radio receiving system employing a space radio receiving system having a plurality of space discharge tubes and means for selectively employing certain of said space discharge tubes for cooperation with wired radio receiving apparatus.

In the drawing, 1 have diagrammatically represented one embodiment of the radio re ceiving system of my invention.

In this specification, the term carrier fre-- quencywill be used to denote those frequencies usually employed in wired radio broadcasting and lying within the range from super-audibility to 100 kilocycles, while the term radio frequency will be employed as denoting those frequencies lying within the range commonly used in space radio broadcasting from 500 kilocycles to 1500 kilocycles.

My invention is directed to providing a radio receiving system having a plurality of radio frequency amplification stages and a de tector and audio frequency system. This 100 V fication whereby the amplified carrier frequency energy may be directed over a wired radio carrier frequency circuit path to the input of a selective filter system for the selection of any desired carrier frequency channel. The output of this filter system is then directed by the unitary switching arrangement to the input of the space radio detector tube.

Referring to the drawing in detail, an an tenna- 1 and ground 2 comprises a space radio energy collecting system having an inductance 3 electromagnetically coupled to an inductance 4 included in a space radio receiver 11. The inductance 4 is connected in parallel with a capacitance 5 which forms a resonant input circuit for the space discharge radio frequency amplifier tube 6. The output, or anode circuit of the tube 6 includes an inductance 7 electromagnetically coupled to an inductance 8. The inductance 8 is connected in parallel with the variable capacitance 9.

forming a resonant input circuit for another space discharge radio frequency amplifier tube 10. The anode or output circuit of the tube 10 includes an inductance 12 electromagnetically coupled to an inductance 13. Inductance 13 is connected in parallel with a variable capacitance 14 forming a resonant input circuit for a space discharge detector tube 15. A grid leak and condenser 16 is connected to the input circuit to the space discharge detector 15. The resonant circuits 4-5, 8-9, and l3-14 can be adusted for reception of space radio signals at any particu lar radio frequency. The anode or output circuit of space discharge detector tube 15 includes an inductance 17 which forms the primary of an audio frequency transformer having a secondary inductance 18. The inductance 18 is included in the input circuit to a space discharge amplifier tube 19 having an output or anode circuit including inductance 20. The inductance 20 forms the pri mary of an audio frequency transformer having a secondary inductance 21 in circuit with a translating device such as loud speaker 22. Suitable sources of biasing voltage, anode voltage, and cathode current are provided, as shown, in a conventional manner.

According to my invention the resonant circuit 8-9 is connected to the control electrode of the space discharge tube 10 through two movable switch blades 24 and 25 respectively circuit 13 and 14 is connected to the grid condenser 16 through switch blades 36 and 37 respectively in engagement with the interconnected contact terminals 38 and 39. The switch blades 36 and 37 can be moved into engagement with the contact terminals 40 and 41 respectively. An insulating bar 42 is pivotally connected to all of the switch blades whereby the switch blades can be moved in unison to either a wired radio or space radio operating position.

Further in accordance with my invention, the contact terminals 28 and 29 are connected through coupling means 46 to power lines 47 and 48 upon which carrier frequency energy is impressed. This carrier frequency energy comprises several program channels at several discrete carrier frequencies. The coupling means 46 comprises a device for effecting the transfer of carrier frequency energy from the lines 47 and 48 but which substantially prevents the transfer of the commercial power carried by the lines 47 and 48.

The contacts 34 and 35 are connected to an inductance 49 comprising the primary of an audio frequency transformer having a secondary winding 50. The secondary winding 50 is connected to the input of awired radio filter 51. The wired radio filter 51 comprises means for electrically selecting one of the carrier frequency program channels before referred to. The output circuit of the wired radio filter 51 is connected to the contact terminals40 and 41. When, in the operation of my radio receiving system, it is desired to receive space radio signals, the insulating bar 42 is positioned as shown in the drawing whereby the space radio receiver circuits are completed in a normal manner. Signaling energy is collected by the space radio energy collecting system 1-2 and amplified through the space discharge radio frequency amplifier tubes 6 and- 10. The amplified signals are detected by the space discharge detector tube 15 and subsequently amplified by the space discharge audio frequency amplifier tube 19 for audible reproduction of the program by the loud speaker 22. V

For'operation of my radio receiving system to receive wired radio signals, the bar 42 is moved whereby the switch blades 24, 25, 30, 31, 36, and 37 are moved into engagement with the contact terminals 28, 29, 34, 35, 40

and 41 respectively. In this position the carrier frequency energy comprising several discrete carrier frequencies is introduced into the input circuit of the last stage of radio frequency amplification of the space radio receiver 11 comprising space discharge radio frequency amplifier tube 10. The signal energy output of space discharge amplifier tube 10 Will be directed through the inductance 49 and inductance 12. However, the inductance 12, being especially designed for radio frequency currents, will be substantially ineffective for transfer of energy at carrier frequencies. The transformer lth-50, however, is especially designed for transfer of carrier frequency energy. The wired radio filter 51 can now be manipulated for the selection of any desired carrier frequency program as amplified by the space discharge amplifier tube 10. The signal energy output from the wired radio filter system 51 will then be introduced into the input circuit to the space discharge detector tube 15. The demodulated signal energy output from the detector tube 15 then acts through transformers 17-18 and is amplified by the space discharge amplifier tube 19 for audible reproduction of the program over loudspeaker 22.

It will now be obvious that I have provided a novel radio receiving system for receiving either wired radio or space radio signals. An especial feature of my invention resides in that a plurality of space discharge tubes are employed for amplification of space radio signals at a selected frequency, while but one of these space discharge tubes is utilized for amplification of wired radio signals at a plurality of discrete carrier frequencies. Another feature resides in that a selective filter system and carrier frequency circuit path is provided for selective connection between a high frequency amplifier tube and a detector tube of a space radio receiving system. Although I have shown a preferred embodiment of my system it will, of course, be understood that changes can be made therein without departing from the intended scope of my invention. I do not therefore desire to limit myself to the foregoing except insofar as may be pointed out in the appended claims.

What I claim as new and original and desire to secure by Letters Patent of the United States is:

1. A radio receiving system comprising, a space radio energy collecting system, a plurality of radio frequency amplification stages for amplifying radio frequency signals, wire lines for conveying carrier frequency signals, means for partially utilizing said amplification stages to amplify said carrier frequency signals, a demodulation and audible frequency amplification system, different circuit paths having different frequency characteristics for transfer of signaling energy from said amplification stages to said demodulation and amplification system, one of said circuit paths including a selective filter system, and means for selectively rendering said circuit paths effective for transfer of signaling energy from said amplification stages to said demodulation and audible frequency amplification system. Y

2. A radio receiving system comprising, a space radio energy collecting system for receiving space radio signals, a plurality of space discharge tubes for amplifying said signals at radio frequencies, a source of carrier frequency signals, means for connecting one of said space discharge tubes to said source of carrier frequency signals, a carrier frequency output circuit for said last mentioned space discharge tube, a radio frequency output circuit for said last mentioned space discharge tube, a demodulation and audible frequency system common to said output circuits, and means for rendering either of said output circuits effective for transfer of energy from said last mentioned space discharge tube to said demodulation and audible frequency system.

S. A radio receiving system comprising, a space radio energy collecting system, a plurality of amplification stages for amplifying space radio signals, wire lines for conveying carrier frequency energy, switching means for connectingsaid wire lines to said amplification stages whereby said amplification stages are only partially used for the amplication of said carrier frequency signals, a demodulation and audible frequency system, a plurality of circuit paths of different frequency characteristics for transferring energy from said amplification stages to said demodulation and audible frequency system, switching means for selectively rendering said circuit paths effective for transferring energy from said amplification stages to said demodulation and audible frequency system, and common means for actuating said switching means.

CHARLES R. ROWE. 

